<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        #inp:focus{
            background: url(https://ss1.bdstatic.com/70cFvXSh_Q1YnxGkpoWK1HF6hhy/it/u=1577759731,3108671782&fm=27&gp=0.jpg)
        }
    </style>
</head>
<body>
    
    <input id="inp" type="text">

    <input type="text" name="" id="">

</body>
</html>